Ringer sound control



March 1956 o. w. HENRIKSON 2,737,651

RINGER SOUND CONTROL Filed Oct. 5, 1954 2 Sheets-Sheet l FIG.2

INVENTOR. OSCAR w. HENRIKSON ATTY.

March 6, 1956 O. W. HENRIKSON RINGER SOUND CONTROL Filed on. 5, 1954 2 Sheets-Sheet 2 llllllllll 42 FIG. 4a. FIG. 4b

INVENTOR.

OSCAR W. HENRIKSON By QM ATTY.

nited States Pater-it O RINGER SOUND CONTROL ()scar W. Heurikson, Chicago, 11]., assignor to Automatic Electric Laboratories, Inc., Chicago, Ill., a corporation of Delaware Application October 5, 1954, Serial No. 460,359 7 Claims. (Cl. 340-401) This invention relates to electromagnetically operated ringing devices and particularly to improvements in volume controls for telephone subscriber substation ringers. This invention finds its chief application to ringers of the type generally known as polarized and then especially to ringers where it is found desirable to provide means for adjusting the travel of the armature of the electromagnet with respect to its pole-piece.

My invention is particularly applicable to ringers of the type substantially described in my copending application Serial No. 229,623 filed June 2; 1951, and which employ a pair of electromagnets the pole-pieces of which alternatively operate upon the arms of an armature pivoted between the magnets. A clapper rod staked into the armature to the opposite end of which a clapper is secured is thus caused to vibrate thereby causing the clapper to alternately strike each of a pair of gongs. The intensity level of the sound produced by the contact of clapper and gong is determined partly by the amplitude of movement of the clapper rod which in turn is determined by the degree which the armature is permitted to move about its pivot. Thus if a means is provided whereby the armature travel can be adjusted an adjustment in intensity level of the ringer sound is also achieved.

Generally stated then, it is the primary object of my invention to provide a means for controlling the sound level of a telephone subscriber station ringer to any desired intensity through a new and novel means for adjusting the movement of the ringer armature with respect to its pole-piece.

It is another object of my invention to provide such adjusting means of a simplicity and ease of operation that the adjustment can readily be made by the telephone subscriber to suit individual requirements.

An important feature of my invention is a novel finger wheel which may be rotated to anumber of positions corresponding to any number of sound intensity levels available, the finger wheel at the' same time serving as the means whereby the movement of the armature is limited.

Another feature of my invention is the fact that an ad justment in the armature gap accomplishes a corresponding adjustment in the striking force of the clapper.

This invention will become clear from a reading of the detailed description which follows taken in connection with the accompanying drawings of which:

Fig. 1 shows a plan view of the ringer'in which the relative position of the armature and clapper rod and the pole-piece and finger wheel are clearly presented,

Fig. 2 is a side elevation of the ringer in which is shown the finger wheel in its position between'a pole-piece and the armature and extending through the base-plate of a mounting in a subscriber'substation. The Figs. 2-4 are shown partly broken to more clearly show'the relation of the parts. 4

Fig. 3 is an end view of the ringer in which the of the finger wheel is further illustrated, and

Fig. 4a and b show the details of the finger wheel, its

position mounting and its cooperating elements, Fig. 4b being a section view taken along the line b-b of Fig. 4a.

A substation ringer embodying the sound level control constructed according to the present invention comprises a pair of electromagnets 10 and 11 rigidly secured to a bracket 12 by means of the screws 13 as may be seen in Figs. 1 and 2. The bracket 12 in turn constitutes the means whereby the ringer assembly may be installed on a base 5 of a subscriber substation as by the screws 14. Composition or rubber feet 6 may be secured to the base 5 in any convenient manner. An armature yoke 15 having a pair of parallel lugs 16 turned at right angles provides a means for pivoting the armature 17. The armature 17 is secured in a proper relationship with the pole-pieces 18.

and 19 of the coils 10 and 11 respectively by means of a four member non-magnetic clamping spring 20. The clamping spring 20 is provided at the extremities of the four members with a pair of lugs 20a and a pair of lugs 20b. The lugs 20a are turned at right angles to the main portion of the spring 20 and are drilled to receive a pivot pin 21 which also passes through suitable holes provided in the lugs 16 of the armature yoke 15. The lugs 20b,

the extremities of the armature Staked to the armature 17 or secured in any convenient manner is a clapper rod 23 to which at the other extremity is floatingly mounted a clapper 24. A wire spring 25 is also staked in the armature 17 and is designed to bias the armature 17 and its stop 20c toward the pole-piece 19 of the electromagnet 11. The spring 25 is held in a stressed position by means of a spring clip 26 which may be mounted to the bracket 12 by one of the screw means 13, the spring 25 passing through and resting ina slot 27 of the clip 26. A pair of permanent magnets 28 and 29 are held in place by slots provided in the spool heads 30 and 31 and the clamping action of the bracket 12 and the armature yoke vide polarization for the armature 17.

A pair of gongs 32 and 33 bracket 12 by the screws 34 bly proper. As is evident from F g. 1, as the electromagnets 10 and 11 are alternately energized, the pole-pieces 18 and -19 will be similarly magnetized causing the armature 17 to be alternately attracted to .the pole-pieces 18 and 19 and thus pivoted aboutthe pivot pin 21. The

est force and thereby produce the loudest ringing when the vibration of the clapper rod 23 reaches its greatest amplitude and when the electromagnet exerts its greatest attraction on the armature 17. is reached, obviously, when the armature 17 is permitted its maximum pivoting motion, that is, when the distance between the armature stops 20c and the pole-pieces-18 and 19 is at a maximum. The electromagnet exerts its greatest attraction when the magnetic flux path is sub? stantially unbroken and this condition in part is accomplished by maintaining at a tuting the residual gap.

The present invention accomplishes simultaneously the adjustment of the aforementioned conditions, namely, the adjustment of the residual gap thus limiting the power "of the armature 17 motion and the adjustment of the adapted to pass through suit secured to the clamping spring a 15. The magnets 28 and 29 serve to promounted on extensions of the completes the ringer assem- This point of greatest amplitude minimum the distance consti spam J limits of the travel of the armature 17, itself. This is accomplished by means of a finger controlled non-magnetic wheel 40 rotatably mounted on an extension 43 of the armature yoke 15, most clearly shown in Fig. 4a. A lug 44 of the yoke and turned at right angles to it provides additional means for securing the ringerfassembly in the required installation as by'the screw means 45. The finger wheel 40 is mounted by mean'sjof aist'iitable shoulder screw 42 which is locked in position by means of a spider compression spring 41 andis provided on its periphery with the knurling 40a to facilitate finger rotation. The finger wheel 40 is so positioned with respect to' the ringer installation that a sector of the wheel 40 'is permitted to extend beyond the base orcasingjas. i's"clearly represented in Figs. 2 and 3. Thus anyfrota tion of the wheel 40 can be accomplished from t re outside of the installation.

Thefinger wheel 40 to achieve its function is essentially a barrel cam having, in'the preferred embodiment of thisinvention, its base in a plane perpendicular with its axis and its operatingsurface generated by rotating a portion of a radial section of'the wheelabout'its axis at: the'same time linearly increasing the altitude "of theradial If such 'a radial section is rotated'forsubstan section; tially a complete revolution an operating surfacewill result which gradually increases its distance from thebase from a minimumata'point to a maximum when that pointis again reached. Thus the'peripherallsurface of the barrel cam will present a substantially'wedge shaped area. "Referring to Figs. 4a and 4b of the'dra'wings 'it. is seen that the point X on the periphery'of the wheel '40 ma be the starting point of the rotation of theradial .section; As' t he section is rotated in a counterclockwise direction as viewed in Fig. 4a the section will achieveits' maximum distance from the base of the wheel 40in one revolution when it again returns to the point X.. The maximum and minimum differential is clearly shown by'the formation of a ridge 45. Since the cam surface is generated by rotating only an outer radial section, a concentric surface perpendicular to the axis of thewheel 4t) compressionspring 41.

A'shoulder 47 is provided on the wheel 40 on the opposite side from its operating surface to maintairrthe proper distance from the armature yoke 15 and to insure proper alignment with its cooperating elements. Also on the sideof the wheel 40 opposite from the operating I tween two jextreme positions As is ,clearlyshown in:

Figffla a sector of the wheel 40 is always interposed be;

tweenthe armature '17 and the pole-piec e 19 Thus assuming the'nor n'al position of the finger wheel 49 to, beas shown'in Fig. 4a, that is, with the cam lobe 58 in .40 remains whichrprovides a flat surface for the seating :of the contact with the'stud pin 40 then, as indicated by thep'osition of the point X, the sector of the barrel cam or finger wheel/40 having the minimum peripheral thickness will bein position between the armature 17 and the pole-piece 'This' is most clearly shown in Fig. 4b. At this position of the wheel 40 the residual gap will beat a minimum; and the armature stop 20c is permitted to contaQ the'pole-piece'19, that is, the minimum peripheralthicknessf of the wheel 40 at this position permits an unimpede'd movement of the armature upon theenergization oflthe 'electromagnets 10and 11. As aresult, at this position the'magn'etic attractive force is greatest and the armature 17 and clapper rod 23 is permitted the greatest,

swingfa'ndthe ringing will be the loudest,

If fthe: finger wl1eel 40 is now rotated in a clockwise direction as viewed in Fig. 4a, its other extremeposition will be determined bythe other side, of the cam lobeS contacting 'the'stud pin 49 and a sector of thewheel .40

with the maximum peripheral thickness will be inter- 1 posed between the armature 17 and the p le-pie ce 19.,

At this. extreme position the cam wheel 40 effectively prevents any movement of the armature 17 and at this position also with the armature 17 held in its extreme position the residual gap will be at a maximum. The clapper 24 will thus be prevented from striking the gongs and the ringer will remain silent during any encrgization of the electromagnets 10 and 11.

As will be evident from the above description there will be an unlimited number of intermediate positions to which the finger wheel 40 may be rotated, each position as described above, corresponding to a certain level of ringing loudness. To aid the subscriber in selecting the degree of loudness desired, however, indicia have been provided on the finger wheel 40 representing seven positions of ring'ing'loudness. The number 1, for example, represents the extreme position of the wheel 40 and at which position the ringing will be the loudest. At this position the number 1 will be readable on the sector of the wheel 40 projecting outside. of the casing. On

the othe'r'extreme, the number 7 represents the silent, position of the'wheel and represents the position at which, the sector'of maximum peripheral thickness is interposed between'the'pole-piece 19 .and the armature. 17 Simil a'rly, t he numbers 2" through 6 represent intermediate positions to which the wheel 40 may be rotated.

While what preferred embodiment of my invention it is to be understood that various modifications may be made in the.

Stil'LiCtllI'o atld arrangement of the component parts without departing from the scope of the following claims.

What is claimed is: i

1. In a ringer, in combination, electromagnet means hand,.said means having a portion extending into said.

space between said pole-piece and said armature, said ad usting means adapted to progressively limit said armature travel as said adjusting means is rotated.

2. In a ringer, in combination, electromagnet means having a pole-piece, an armature pivotally connected on said ring and adapted to travel between predetermined limits as said electromagnet means is energized, a bracket mounted on said ringer adjacent the space between the.

armature and said pole-piece, an adjusting means rotatably mounted on said bracketandtfreely rotatable. be-

tween, said pole-piece and said armature, said adjusting meansadapted to present a cross section of progressively increasing dimensionbetween said pole-piece and said armature, as said adjusting means is rotated to thereby progressively limit said armature travel.

3.-In combination in a telephone substation ringer, electromagnet means having a p'ole-piece, an armature pivotally. mounted in said ringer, and'adapted to pivot between predetermined limits as said electromagnet is periodically energized, a clapper rod secured to said armature and having a clapper. mounted onthe extremity thereof, a pair of gongs associated with said clapper, said clapper adapted to alternately strike each of said gongs as said armature is pivoted, the sound intensity level of said gongs being a function of said predetermined limits, a rotatable wheel mounted in said ringer, a sector of said wheel passing between said pole-piece and said armature, the periphery of said wheel progressing from a minimum to a maximum thickness, the said sector ofsaid wheelpassing between said pole-piece and said armature varying in thickness as said wheel is rotated:

has been described is considered to be the,

casing and having means provided on the periphery thereof to facilitate rotation by means of a finger.

5. In an electromagneticafiy operated ringer for use in telephone substations, said ringer having an armature operated clapper and gongs associated therewith and in which the sound intensity level of said ringer is a function of the limits of the armature travel, a sound level control comprising a Wheel mounted in said ringer, an annular portion of said wheel having a cross-section of progressively varying thickness such that as said wheel is rotated said limits of said armature travel will be correspondingly progressively limited to thereby progressively limit said sound intensity level, said annular portion of said wheel also projecting externally of said substation and said wheel provided with means on the periphery thereof to facilitate finger rotation of said Wheel.

6. In a sound level control as described in claim 5, said annular portion of said wheel provided with indicia thereon, each of said indicia corresponding to representative levels of sound intensity, said indicia so positioned that as said wheel is rotated said indicia are successively visible externally of said substation.

7. In combination in a telephone substation ringer, eleotromagnet means having a pole-piece, an armature pivotally mounted in said ringer and separated from said pole-piece by a predetermined gap, said armature adapted to pivot between predetermined limits as said electromagnet is periodically energized, a clapper rod connected to said armature and adapted to vibrate as said armature is pivoted between said limits, said clapper rod having a clapper mounted on the extremity thereof, a pair of gongs associated with said clapper, said clapper adapted to alternately strike each of said gongs as said armature is pivoted, the sound intensity level of said gongs determined by the striking force of said clapper, said striking force being a function of said predetermined gap and said predetermined limits, a rotatable non-magnetic wheel mounted in said ringer, a sector of said wheel passing between said pole-piece and said armature, a peripheral portion of said wheel progressing from a minimum to a maximum thickness, the said sector of said Wheel thereby interposing a cross-section between said pole-piece and said armature of varying thickness as said wheel is rotated to thereby simultaneously vary said predetermined gap and said predetermined limits whereby said sound intensity level is correspondingly varied.

References Cited in the file of this patent UNITED STATES PATENTS 1,132,249 Ericson Mar. 16, 1915 2,590,500 Bredehoft et al. Mar. 25, 1952 2,643,634 Hoyka June 30, 1953 

